Research On Parametric Modeling Method Of Urban Road Entity Of Real Three-dimensional Model

Real three-dimensional(3D)Model has the advantages of pretty intuitive visual effects,rich information,and being quantifiable.It has a wide range of applications in many fields such as national defense security,urban planning,smart cities,and environmental protection monitoring.With the development of new basic surveying and mapping,the construction of 3D urban model oriented to geographic entities has become the key content in the construction of basic surveying and mapping.The urban road is an important part of the urban scene and the basic infrastructure of the national economic infrastructure.The construction of the road solid model has important research significance and research value in the real three-dimensional model construction.However,the existing 3D modeling methods of road entities are limited in the research and application of the new basic mapping solid model because these methods are limited to the geometric topological level and lack of professional knowledge of road design standards and specifications.In addition,in these methods,the integration of modeling rules and modeling process is dense,and it is difficult to reuse the modeling rules..Based on this,this thesis conducts a 3D modeling study of urban road entities,designs a unified parametric expression,proposes a modeling method based on multi-level semantic constraints,and completed a large-scale construction of urban road entity models.The main research content and research results are as follows:1.This paper studies real-world 3D modeling-related technologies,and explores the concept and modeling content of geographic entities;designs the road entity 3D modeling technology route for new-type basic surveying and mapping.2.This paper introduces the preprocessing method of road centerline data,including sampling of road centerline,processing of intersections,and calculation of spatial posture,and constructs a road network for solid modeling of urban roads.3.This paper analyzes the modeling parameters of urban road entities,and introduces the road construction design parameters;then the modeling parameters corresponding to the graphic elements are organized and stored in a hierarchical manner to form a unified parametric expression of urban road entities,to make the description of urban road entities and graphic elements clear,and facilitates reuse of the modeling knowledge.4.This paper proposes a multi-level spatial semantic constraint modeling method,and studies the triangulation,texture mapping,and fusion algorithms of models and scenes.Among them,in the modeling rules,for the connection problem of road sections,this paper combines the "Design Specification for Highway Alignment" by setting the curvature radius threshold and precision control factor for the connection points to achieve smooth transition and seamless connection of road sections.5.This paper conducts experiments on two sets of data in Hohhot and Hong Kong,and compares with the oblique photography model to verify the effectiveness of the proposed method and the superiority.